# What is Volts: Definition and 105 Discussions

The volt (symbol: V) is the derived unit for electric potential, electric potential difference (voltage), and electromotive force. It is named after the Italian physicist Alessandro Volta (1745–1827).

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1. ### Are lost volts the difference between EMF and terminal potential difference?

Are lost volts the difference between EMF and terminal pd?
2. ### High Volts Low Amps: Sustaining Power with Arduino & MOSFET

Hello, I have a limited knowledge of electronic engineering, so please bear with me. I want to Have a device that I could have high volts with low amps and have the power be sustained. Then I could possibly use an Arduino with a silicon carbide MOSFET to do precise pause with modulation. The...
3. ### Drawing Electric Arcs at 230 Volts

Hi everyone :) I open this discussion because I would like to know how electric arcs are able to be drawn. Indeed, I have been told that it is perfectly possible to draw electric arcs at very low voltage, by simply putting in contact two electrodes and then drawing them apart. I wanted to try...
4. ### How to start LM317 regulator from 0 Volts

I want to make power supply from LM317 which starts from 0 volts instead of 1.25 volts. I have seen method of using diodes and zeners but I think there maybe a better way. We know Voltage across R1 (see image 1) is 1.25V. So if I take the output across R2 rather than at OUT of IC, won't I get...
5. ### Understanding Power Equations: How Do You Solve for V2 and R in Ohm's Law?

Hello everyone new here :) I've recently enrolled myself in a computer technician course and I've encountered a few (basic) electrical sums. I have absolutely no electrical background, and the course mentioned no requirement of such, but I'm already being presented with work I have no idea of...
6. ### How does mechanical torque affect generator volts and amps?

Hello! today I have a question regarding the most efficient way to generate electricity by moving a magnet across a coil. The theoretical magnet would be moving in a circular motion fixed to the outer circumference of a driver wheel like in many simple generators, how does the physical torque...
7. ### B Is Earths' potential of 0 volts valid throught the Universe?

We have set the Earths' Voltage at zero volts but is this 'earth voltage' applicable throughout the Universe. If not, is it relative in the same manner as spacetime and is it calculatable?
8. ### What does a lightbulb prefer? Volts or Amps?

Lightbulbs are rated in watts. Watts = energy/time = volts*current Does it matter if you have a very low voltage source with a very high current or a very high voltage with a very low current? If the voltage and current multiplied meets the power rating, what should it matter what proportion...
9. ### How to cut down 12 volts to 1.5 volts

I know one can use a LM317 to cut 12 volts dc to 1.5 volts but can one use resistors? I have a wall clock that runs a small motor to wind spring and it powered by a c battery you can run on more voltage without out damage to any thing as it only run for 1 second every 2 minutes. I tried a 30 ohm...
10. ### Old 6 volt auto headlight in series with 1154 on 12 volts

If one hooks a 1154 and an old 6 volt automotive headlamp in series and powers it with 12 volts will the headlamp being that it is higher wattage cause all the current flow thru the smaller wattage bulb causing it to burn out?
11. ### Kinetic energy in electron volts

Homework Statement How much kinetic energy is in electron volts? Homework Equations Kinetic energy = 1/2 mv2 1 electron volt = 1.6 x 10-19 J The Attempt at a Solution [/B] It's a bit unclear to me what the question is asking, since no context at all is given. It's one of the questions in...
12. ### Where Can I Find a Step-Up Adapter for 12V to 400V Charging?

Good day. I'm looking for designing/purchasing a step up adapter with the capability of stepping up a 12v battery source (like a car battery) to 400v for the purpose of charging a 1800uf, 450v, capacitors to 400v. Can you point me to the right direction? Thanks.
13. ### What is the correct equation to solve this power and voltage problem?

Homework Statement A 4.0 Watt toy motor is connected to a secondary circuit of a transformer with 60 loops and a current of 0.10 A. The primary voltage is 120 V Homework Equations Vp / Vs = Ip / Is Ip = Pp / Vp[/B]The Attempt at a Solution 1. [/B]Vp / Vs = Ip / Is 120 V / 40...
14. ### Confused with the relationship between Volts, Current, and Power

Homework Statement For an engineering assessment (first year with no electrical background), we are using a solar panel to power an element for a distillation system. we have calculated our heat energy output requirement that we need from our heating element as being 800 J/s. For simplicity we...
15. ### Signal measurement ~50 pico volts

Hi, my question may be too open ended in which case some help defining it would be helpful. The signal I wish to measure is estimated to be ~50 pico volts in amplitude generated in an HF AT-cut quartz crystal. Basically all the signal power will be at the fundamental mode resonant frequency...
16. ### Is it possible that there is a 220 volts but low current?

I read at the power outlet,the meter detect 220 volts but the split type AC doesn't work.it happens when I used the back up generator.
17. ### Limiting amps and volts from a battery

I have a project that involves a small motor, and the battery powering it would blow the motor in an instant without proper use of resistors. The battery I'm using is rated at 9.6 volts and 1600ma. The motor however, is rated at 3 volts and 0.3 Amps. I would like to go just under these ratings...
18. ### What is the lost volts in this circuit?

Homework Statement A cell has an e.m.f =1.5v and Internal Resistance = 0.75Ω is connected as shown in the following circuit ( circuit has 3Ω resistor under the battery) (I) Calculate the reading on the voltmeter. (Ii) what is the value of the "lost volts" in this circuit? Can anyone help me...
19. ### Maximizing Amps in Circuit with 90W Power Supply

So, I know the basic equation of W=V*A, but how would I physically do this in a circuit? Say I have 90W=19V*4.74A (http://www.chargerbuy.com/replacement-hp-90w-smart-ac-adapter-19v-474a.html?gclid=CjwKEAiAi-_FBRCZyPm_14CjoyASJAClUigOPligEwQ9DD87xaDL8SQcvxNtWCeo_2nl68GmdozOoxoCbW3w_wcB) for...
20. ### Voltage derivation for charged particles

I have a very weak understanding of the particle modelling of electrical phenomena.1: Electric field =\frac{Force}{Magnitude of charge} 1 is The definition of electric field on a particle (?) 2: Force = \frac{Q1*Q2*K}{R^2}\\ 2 is Coulombs law, to find force between two particles. 3...
21. ### How many volts is required for a tiny spark to be created?

Homework Statement How many volts is required for a tiny spark to be created in electrostatics? Homework Equations No equations The Attempt at a Solution 5,000 watts
22. ### Understanding Inputs and Outputs for Specific Project

<< Mentor Note -- Please read to the end of this thread -- important information about AC Mains connected projects is discussed >> Hello everyone, I am an electrical engineering student (though in the very beginner stage of it), and I could really use some help with understanding inputs and...
23. ### What does it mean to say a battery is however many volts?

For instance, at a point 1 meter from a 1 nC charge the voltage (potential difference) from the formula V = Kq/r, is given as 9 volts, 9 J/C. So what does it then mean to call a battery 9V, 9 J/C? Is this a battery capable of taking a 1 C charge from infinity and pushing to within 1m of a 1 nC...
24. ### Is it possible to increase the amps within/along a circuit?

Let's say you have a basic series circuit with a battery power source that has 12 volts. You also have a load of some sort with 3 ohms of resistance. Therefore you'll have 4 amps of current throughout the circuit. Is it possible to add some item within or along the circuit (and before the load)...
25. ### Upgrading a 12V Alternator to Produce a higher output Volts

Hi could anyone please help with this:- I have a 12V 90Ah automobile alternator. is there a way to increase the output volts beyond the 14/13.8v to say 192v?
26. ### Using 8 Mega Volts DC as electric energy source?

If a fusion reactor could be constructed that runs on Li-7 and hydrogen, and if the energy produced by that reactor where extracted with a direct charging setup, like in a nuclear battery emitting alpha particles, the voltage produced would be the stupendous voltage of 8 mega volts. Now, how do...
27. ### 555 timer IC - Calculating resistance needed

Voltage = 9.0 V, Current = 20 mA, Capacitor (C) = 10 microF, Resistance before (too high) [R_A = R_B] = 10 k Ohms. In a a-stable oscillator, calculating the resistance needed for two resistors (R_A = R_B) to discharge and charge a capacitor (C) so that a LED does not blow. Currently my circuit...
28. ### 12 volts to 120 volts the easy way?

Living in a remote desert location, I have to generate my own power from solar. Big loads require big inverters, and for me sine wave is a must, not modifieed sine. Higher voltage inverters allow more batteries in a string meaning more storrage capacity in that string and since multiple...
29. ### How many volts does a cathode ray tube emits?

I don't know a lot about classical physics but I was wondering how many volts a cathode ray tube emits?
30. ### Electricity Question Amps & volts confusion

Homework Statement [/B] A) If a laptop computer charger is designed for use in a country where mains voltage is 230V. Will the user still be able to charge the laptop computer in a country where the mains supply is 110V? B) Also what happens if a 110V charger is used in a country where the...
31. ### EMF Radiation Measurement: 15 Milli Volts vs Milli Volts/Meter

I measure the Electromagnetic Field Radiation at a point for example x distance from a source, and i am reading for ex. 15 milli volts per meter. Are these 15 millivolts per meter, equals to 15 milli volts ? I mean, if i do the opposite procedure, and receive a reading of 15 milli volts, at a...
32. ### Why is the terminology in electrical engineering so redundant and confusing?

I've been trying to brush up on my electrical engineering skills and have been working on the circular and redundant terminology of amps, volt, ohms and watts. It seems to me it all comes down to a quantity of electrons (i.e. coulombs). And, for various reasons perhaps the number of electrons...
33. ### How many volts can a multimeter read?

I have only tested mine (it is a cheap one \$20) it on a 9V battery, what is the limit? My multimeter starts from 1000V DC then 200,20, 2000m,200m... I am a noob with this so sorry if I don't make sense
34. ### Why is power equal to voltage times current?

I don't have an intuitive understanding of this. To me it seems that power should be related to just current, since this is the measurement of how the charge is flowing. Volts and current are inextricably related, true? So then why P=VI instead of P=I? Thank you
35. ### Designing a display for Watts, Volts and Ohms.

I am working on a small project and having those values shown in real time on the device will be helpful. I don't have much room as it is. I currently have one of those little 1s-6s volt meters used by RC hobbyist and use my multimeter to check resistance. My goal is to have something around...
36. ### Finding the kinetic energy of a proton in megaelectron volts?

Homework Statement Charged particles such as protons are accelerated to high velocities and are allowed to collide with atomic nuclei to probe their internal structure. The electric potential outside of a point charge Ze. A) A lead nucleus (Z - 82) is approximately described as a sphere of...
37. ### Amperage of 50 farads at 12 volts

Dear Experts If I have 50 farads at 12 v, does this mean this power bank can discharge 600amps in 1 second based on 1 farad = 1 amp per second per volt ? Thanks for reading. Regards Ramone
38. ### VCalculate the potential difference (in volts) between the terminals of the battery

I reduced to equivalence capacitance and found the potential difference between the nodes based on what was provided using the rules of parallel and series and my final answer doesn't match the answer given. I have a test in two days and have been studying this along with other subjects. Could...
39. ### Square wave symmetric around zero volts

Hi everyone For a pre-lab, I am asked to draw a square wave symmetric around zero volts. I am not sure what this graph looks like, can someone give me an example? Thank You
40. ### Which Particle Has More Electric Potential?

Homework Statement given a uniform electric field direct straight downward. If I have two particles, one is positive and the other is negative, both align horizontally (at the same height) inside the field. Which one has more electric potential? Homework Equations The Attempt...
41. ### Does volts and amps get at half while charging multiple batteries?

Hi guys (and gals) Say, i have a solar panel rated at 100w 12v with the following specs: Short circult current(Isc): 6.01A Open circuit voltage(Voc): 21.5V Optimum operating current: (Imp) 5.52A Optimum operating voltage: (Vmp) 17.78v Maximum power: (Pmax) 100W And I decide to...
42. ### An electric potential is given in volts by

Homework Statement An electric potential is given in volts by; \phi (x,y,z) = 20x - 12y^2 +2yz, where x,y and z are measured in metres. Find the magnitude of the electric field E at the point(1,1,3). Homework Equations E = -\nabla \phi The Attempt at a Solution -\nabla...
43. ### Converting de Broglie Wavelengths for Electrons at Different Voltages?

Homework Statement What possibility can be the ratio of the de Broglie wavelengths for electrons accelerated through 50 volts and 200 volts, initially having same wavelengths? Homework Equations I have literally no idea how to convert volts into energy, here i somewhat i think, Energy=...
44. ### What's more important amps,r watts or volts?

Last night i did an experiment with a halogen bulb, rated at 12v 100w (8.33amps) dc. The exact model is this: http://inpcars.com/spotlights/motortrendmts43707-i.jpg I used to turn that bulb on, 3 serial batteries 1.5v "aaa" @ 0.4ah = 4.5 @ 0.4ah (1.8watts), and it turn on a little bit...
45. ### Is resolution strictly defined in volts?

I didn't know that resolutions are defined in volts until today. I never wrote units to them. I read in wiki that... So it can be expressed as both? I'm confused. Must I write units to resolution, or can I interchange them between bits and volts?
46. ### Force per unit length between two parallel whires of +/- X volts

Homework Statement Two parallel whires, separated by a distance D (midpoint distance), are charged with a current density L (each whire has a radius R). If the whires have the potential +/- X Volts, what is the force per unit length between them? Homework Equations B = μ0*I /(2πr) is...
47. ### Understanding Electron Volts, Temperature & Boltzmann's Constant

I need the electron volt in atomic units (mainly because I need "atomic unit" temperature). I believe that one atomic unit of temperature is eV (electron volts) / kB (Boltzmann's constant). So I know that the elementary charge e = 1 = h-bar. How do i get eV, temp, Boltmann's constant...
48. ### Question on Amps kills not Volts

From what I understand about electricity, it would be the amps flowing through your heart not through the circuit of which you touch. If I have a 2 amp circuit on a nine volt battery, it would not kill me because there is only 9 volts. Ohm's law says this will be drastically reduced by the...
49. ### How to get 12 volts from electrical outlet?

Hi everyone, I need to power up some small LEDs in series and I need about 12 V total. I can use an A23 12 V energizer battery to achieve this but I want to know if I can use an electrical outlet to do it. So I would need to go from about 120 V (standard North American output) down to 12 V...
50. ### Will a 220 volt choke ballast work the same at 110 volts?

If I use a choke ballast rated for 220 volt at 110 volts, will it still work the same? In other words, if the label says 220 volts 400 watts, will it still operate at 400 w from 110 volts or would the output be reduced to 200 watts?